Who owns Omeros Corporation (OMER)
Which tracked institutional funds hold OMER, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See OMER company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on OMER is one-sided between 2025-Q4 and 2026-Q1: 10 added or opened and 55 trimmed or exited — on balance reducing.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
OMER’s largest tracked holder by dollar value, VANGUARD GROUP INC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes OMER more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in OMER divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 161 tracked filers holding OMER, 100 increased or opened the position and 65 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in OMER between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 6
- VANGUARD CAPITAL MANAGEMENT LLC$32M
- VANGUARD PORTFOLIO MANAGEMENT LLC$8M
- VANGUARD FIDUCIARY TRUST CO$5M
- Prosight Management, LP$2M
- MARSHALL WACE, LLP$861K
- Headlands Technologies LLC$527K
Full exits 8
- VANGUARD GROUP INC$60M
- KOTLER KEVIN$16M
- Informed Momentum Co LLC$4M
- AlphaQuest LLC$1M
- TWO SIGMA ADVISERS, LP$1M
- Verition Fund Management LLC$1M
Largest adds
- Polar Asset Management Partners Inc.$930K
- Clutterbuck Capital Management LLC$592K
- FIFTH THIRD BANCORP$395K
- BNP PARIBAS FINANCIAL MARKETS$320K
Largest trims
- BlackRock, Inc.$31M
- INGALLS & SNYDER LLC$22M
- UBS Group AG$13M
- D. E. Shaw & Co., Inc.$12M
- STIFEL FINANCIAL CORP$12M
- NOMURA HOLDINGS INC$11M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 5,309,626 | $56M | 13.6% | 2026-Q1 |
| INGALLS & SNYDER LLC added | 3,559,423 | $38M | 9.1% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 2,983,259 | $32M | 7.6% | 2026-Q1 |
| UBS Group AG added | 2,340,731 | $25M | 6.0% | 2026-Q1 |
| STATE STREET CORP added | 1,919,575 | $20M | 4.9% | 2026-Q1 |
| STIFEL FINANCIAL CORP added | 1,831,585 | $19M | 4.7% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,752,323 | $19M | 4.5% | 2026-Q1 |
| Corient Private Wealth LLC added | 801,411 | $8M | 2.0% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 718,675 | $8M | 1.8% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 582,512 | $6M | 1.5% | 2026-Q1 |
| BANK OF MONTREAL /CAN/ trimmed | 568,426 | $6M | 1.5% | 2026-Q1 |
| NORTHERN TRUST CORP added | 563,867 | $6M | 1.4% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 492,345 | $5M | 1.3% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 485,030 | $5M | 1.2% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 410,609 | $4M | 1.0% | 2026-Q1 |
| MORGAN STANLEY trimmed | 317,892 | $3M | 0.8% | 2026-Q1 |
| Clutterbuck Capital Management LLC added | 300,000 | $3M | 0.8% | 2026-Q1 |
| Itau Unibanco Holding S.A. | 180,000 | $3M | 0.7% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP trimmed | 286,474 | $3M | 0.7% | 2026-Q1 |
| Badgley Phelps Wealth Managers, LLC | 263,556 | $3M | 0.7% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 260,048 | $3M | 0.7% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 204,805 | $2M | 0.5% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 202,893 | $2M | 0.5% | 2026-Q1 |
| Polar Asset Management Partners Inc. added | 200,000 | $2M | 0.5% | 2026-Q1 |
| Jump Financial, LLC trimmed | 195,824 | $2M | 0.5% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 187,300 | $2M | 0.5% | 2026-Q1 |
| Invesco Ltd. added | 180,629 | $2M | 0.5% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 179,594 | $2M | 0.5% | 2026-Q1 |
| Prosight Management, LP new | 174,800 | $2M | 0.4% | 2026-Q1 |
| Bank of New York Mellon Corp added | 166,246 | $2M | 0.4% | 2026-Q1 |
| Nuveen, LLC added | 154,201 | $2M | 0.4% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 145,307 | $2M | 0.4% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN trimmed | 118,343 | $1M | 0.3% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC added | 117,948 | $1M | 0.3% | 2026-Q1 |
| Ancora Advisors LLC added | 115,000 | $1M | 0.3% | 2026-Q1 |
| HighTower Advisors, LLC added | 110,630 | $1M | 0.3% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. trimmed | 66,990 | $1M | 0.3% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 107,293 | $1M | 0.3% | 2026-Q1 |
| RHUMBLINE ADVISERS added | 102,818 | $1M | 0.3% | 2026-Q1 |
| Susquehanna Portfolio Strategies, LLC | 92,759 | $980K | 0.2% | 2026-Q1 |
| Cambridge Investment Research Advisors, Inc. added | 88,568 | $935K | 0.2% | 2026-Q1 |
| MARSHALL WACE, LLP trimmed | 81,517 | $861K | 0.2% | 2026-Q1 |
| AMERICAN FINANCIAL GROUP INC | 64,113 | $677K | 0.2% | 2026-Q1 |
| Quantinno Capital Management LP added | 61,541 | $650K | 0.2% | 2026-Q1 |
| MINDSET WEALTH MANAGEMENT, LLC added | 59,500 | $628K | 0.2% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 58,178 | $614K | 0.1% | 2026-Q1 |
| MML INVESTORS SERVICES, LLC trimmed | 57,675 | $609K | 0.1% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 56,908 | $601K | 0.1% | 2026-Q1 |
| DEUTSCHE BANK AG\ added | 55,030 | $581K | 0.1% | 2026-Q1 |
| COLDSTREAM CAPITAL MANAGEMENT INC added | 54,130 | $572K | 0.1% | 2026-Q1 |
| Brevan Howard Capital Management LP trimmed | 51,163 | $540K | 0.1% | 2026-Q1 |
| Headlands Technologies LLC added | 49,926 | $527K | 0.1% | 2026-Q1 |
| NFSG Corp added | 47,710 | $504K | 0.1% | 2026-Q1 |
| Focus Partners Wealth added | 47,582 | $502K | 0.1% | 2026-Q1 |
| BARCLAYS PLC trimmed | 44,922 | $474K | 0.1% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 41,121 | $434K | 0.1% | 2026-Q1 |
| FIFTH THIRD BANCORP added | 39,000 | $412K | 0.1% | 2026-Q1 |
| AXQ CAPITAL, LP added | 38,815 | $410K | 0.1% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 41,720 | $409K | 0.1% | 2026-Q1 |
| MetLife Investment Management, LLC added | 38,634 | $408K | 0.1% | 2026-Q1 |
| GROUP ONE TRADING LLC trimmed | 38,604 | $408K | 0.1% | 2026-Q1 |
| Optimize Financial Inc new | 38,407 | $406K | 0.1% | 2026-Q1 |
| NOMURA HOLDINGS INC trimmed | 38,237 | $404K | 0.1% | 2026-Q1 |
| SIMPLEX TRADING, LLC trimmed | 37,526 | $396K | 0.1% | 2026-Q1 |
| Walleye Capital LLC trimmed | 34,533 | $365K | 0.1% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 32,778 | $345K | 0.1% | 2026-Q1 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 31,701 | $335K | 0.1% | 2026-Q1 |
| Cerity Partners LLC added | 31,586 | $334K | 0.1% | 2026-Q1 |
| CITIGROUP INC added | 30,790 | $325K | 0.1% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 30,178 | $319K | 0.1% | 2026-Q1 |
| Diametric Capital, LP new | 29,322 | $310K | 0.1% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. added | 29,083 | $307K | 0.1% | 2026-Q1 |
| Vontobel Holding Ltd. added | 28,450 | $300K | 0.1% | 2026-Q1 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC trimmed | 27,000 | $285K | 0.1% | 2026-Q1 |
| Merit Financial Group, LLC new | 26,993 | $285K | 0.1% | 2026-Q1 |
| Virtus Investment Advisers, LLC added | 26,865 | $284K | 0.1% | 2026-Q1 |
| GSA CAPITAL PARTNERS LLP added | 23,967 | $253K | 0.1% | 2026-Q1 |
| FARALLON CAPITAL MANAGEMENT LLC | 23,000 | $243K | 0.1% | 2026-Q1 |
| Stordahl Capital Management, Inc. | 22,860 | $241K | 0.1% | 2026-Q1 |
| HARBOUR INVESTMENTS, INC. added | 22,025 | $233K | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC added | 3,504,157 | $60M | 14.6% | 2025-Q4 stale |
| KOTLER KEVIN new | 905,635 | $16M | 3.8% | 2025-Q4 stale |
| Informed Momentum Co LLC new | 207,480 | $4M | 0.9% | 2025-Q4 stale |
| AlphaQuest LLC added | 82,597 | $1M | 0.3% | 2025-Q4 stale |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 344,500 | $1M | 0.3% | 2025-Q3 stale |
| TWO SIGMA ADVISERS, LP trimmed | 76,100 | $1M | 0.3% | 2025-Q4 stale |
| Verition Fund Management LLC added | 63,493 | $1M | 0.3% | 2025-Q4 stale |
| Cypress Capital Group | 42,000 | $721K | 0.2% | 2025-Q4 stale |
| JACOBS LEVY EQUITY MANAGEMENT, INC trimmed | 85,514 | $703K | 0.2% | 2025-Q1 stale |
| COMERICA BANK added | 38,000 | $653K | 0.2% | 2025-Q4 stale |
| Squarepoint Ops LLC added | 155,496 | $638K | 0.2% | 2025-Q3 stale |
| Man Group plc trimmed | 27,099 | $465K | 0.1% | 2025-Q4 stale |
| ADAR1 Capital Management, LLC new | 25,000 | $429K | 0.1% | 2025-Q4 stale |
| FRANKLIN RESOURCES INC added | 42,577 | $350K | 0.1% | 2025-Q1 stale |
| Engineers Gate Manager LP added | 20,082 | $345K | 0.1% | 2025-Q4 stale |
| SG Americas Securities, LLC trimmed | 18,825 | $323K | 0.1% | 2025-Q4 stale |
| AlphaCore Capital LLC new | 17,647 | $303K | 0.1% | 2025-Q4 stale |
| LOS ANGELES CAPITAL MANAGEMENT LLC new | 30,920 | $233K | 0.1% | 2025-Q4 stale |
| Graham Capital Management, L.P. trimmed | 13,222 | $227K | 0.1% | 2025-Q4 stale |
| Corebridge Financial, Inc. trimmed | 27,403 | $225K | 0.1% | 2025-Q1 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.